1. Technical Field
The present invention relates to a photographing system. More particularly, the present invention relates to a compact photographing system applicable to electronic products.
2. Description of Related Art
In recent years, with the popularity of mobile products with camera functionalities, the demand for miniaturizing a photographing system is increasing. The sensor of a conventional photographing camera is typically a CCD (Charge-Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor. As advanced semiconductor manufacturing technologies have allowed the pixel size of sensors to be reduced and compact photographing systems have gradually evolved toward the field of higher megapixels, there is an increasing demand for compact photographing systems featuring better image quality.
A conventional compact photographing system employed in a portable electronic product mainly adopts a four-element lens structure. Due to the popularity of mobile products with high specification, such as smart phones and PDAs (Personal Digital Assistants), the pixel and image-quality requirements of the compact photographing system have increased rapidly. However, the conventional four-piece lens structure cannot satisfy the requirements of the compact photographing system.
A conventional compact photographing system utilizes fifth-element lens structure for enhancing the image quality and resolution of the photographing system, but the photographing system has a fourth lens element with a concave image-side surface. The outer diameters of the fourth lens element and the fifth lens element would be increased and the total track length of the photographing system would also be increased by such arrangement, so that the compact size demand would be restricted. Therefore, a need exists in the art for providing a photographing system for use in a mobile electronic product that has excellent imaging quality without an excessive total track length.